JP6554449B2 - Radiation immunity test apparatus and radiation immunity test method - Google Patents

Description

  The present invention relates to a radiated immunity test apparatus and a radiated immunity test method for evaluating the electrical immunity (immunity) of an electronic device to radio waves.

  An external radio wave such as a television or radio broadcast wave or a radiation interference wave from an electronic device may intrude into the electronic device (electronic device) and cause a malfunction of the device. For example, the phone may generate audible noise, and certain electronics may cause an unintended restart. For example, there is a radiation immunity test method described in Non-Patent Document 1 as a method for testing and evaluating the electrical strength of an electronic device while avoiding malfunction of the device due to such radio waves. In the test method described in Non-Patent Document 1, a radio-wave anechoic chamber, a signal generator that generates an amplitude-modulated signal, an amplifier that amplifies the signal, an antenna that radiates the signal into the air, and a device under test. Using a system composed of a non-conductive support to be installed, a device under test (ETU: Equipment Under Test) is installed on the surface where the electric field strength is uniform when radio waves are radiated from the antenna. The operation of the device under test is confirmed when a radio wave of an electric field strength defined for is emitted. At this time, the test level is defined as an electric field strength assuming that radio waves from a radiation source such as a wireless device come from a distance. In addition, by determining whether the performance requirement criteria described in Non-Patent Document 2 and Non-Patent Document 3 are satisfied, the resistance of the electronic device to the external radio waves is evaluated. In this test, radio waves are emitted at one time on the entire surface of the device under test so that the electric field strength is uniform.

IEC 61000-4-3 Ed.3.0, “Electromagnetic compatibility (EMC)-Part 4-3: Testing and measurement techniques-Radiated, radio-frequency, electromagnetic field immunity test”, 2006. ITU-T Recommendation K. 43, "Immunity requirements for telecommunication network equipment", 2009. (pp. 14, pp. 16) CISPR 24, "Information technology equipment-Immunity characteristics-Limits and methods of measurement", 1997. Ford FMC 1278, "Electromagnetic Compatibility Specification For Electrical / Electronic Components and Subsystems", 2015. (pp. 44-48)

  By the way, in recent years, with the spread of small terminals having a wireless connection function such as a tablet PC (Personal Computer) terminal and a smartphone, their use in various scenes has begun for the purpose of improving work efficiency. Specifically, in the communication building or data center, the work procedure manual downloaded to the wirelessly connected tablet terminal is displayed, and maintenance work of the communication apparatus is performed while receiving an instruction of the remote operator, and similarly, the hospital In such cases, the patient's chart is displayed on the terminal for examination and treatment. At this time, the wirelessly connected terminal may approach the communication device or the medical device due to its portability, so that the communication device or the medical device may malfunction due to radio waves emitted by the terminal and give a serious influence. I am concerned.

  As described above, the radiation immunity test method described in Non-Patent Document 1 assumes that a radio wave emitted from a radiation source arrives from a distance and enters an electronic device. On the other hand, devices such as tablet PC terminals may approach electronic devices as infinitely as possible because of their portability. In this case, since the electric field intensity of the radio wave emitted by the radiation source is inversely proportional to the distance, the electric field intensity exceeding 30 V / m which is the maximum of the test level specified in Non-Patent Document 1 may be applied to the electronic device Yes, it is not possible to perform a proof stress evaluation that fully considers the actual usage environment.

  Also, assuming that the distance between the radiation source and the electronic device is d, and the wavelength corresponding to the frequency of the radio wave is λ, the region closer than d = λ / 2π is defined as the “near field” and the current wireless device is In a frequency range of 1 [GHz] or more used as a communication frequency, a range of d = 5 [cm] or less corresponds. Since the near field is different from the far field and the electromagnetic field phenomenon (wave impedance, spherical wave / plane wave, etc.), a uniform electric field plane is set for the entire surface of the device under test as in the test method of Non-Patent Document 1. When conducting the radiation immunity test, there is a possibility that the strength evaluation does not take into account the actual use environment of the wireless device as well as the electric field strength. Another test method that simulates such a situation is a radiated immunity test method for small devices such as in-vehicle devices (see Non-Patent Document 4).

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a radiated immunity test apparatus and a radiated immunity test method which enable radiated immunity testing assuming that a radiation source approaches the vicinity of an electronic device. To aim.

  According to a first aspect of the present invention, in a radiation immunity test apparatus, a radiation element for radiating radio waves, moving means for moving the radiation elements in a first direction and a second direction crossing each other, and radiation of the waves. And control means for controlling the moving means such that the radiation element moves at a constant speed in the first direction in the above state.

  According to a second aspect of the present invention, in the first direction, the control means extends from the one end of the test range from the outside by half of the dimension of the application range to the half from the other end of the test range by the half of the dimension of the application range. And moving the radiating element in the second direction by a dimension of the application range, wherein the application range is between the radiating element and the test range. It is set based on the distance.

  In a third aspect of the present invention, when the wavelength of the radio wave is λ, the moving means is installed so that the distance between the radiating element and the test range is smaller than λ / 2π.

  According to the present invention, a radiation immunity test can be performed assuming that the radiation source approaches the vicinity of the electronic device.

The figure which shows the structural example of the radiation immunity test apparatus which concerns on embodiment. The figure which shows the operation example of the radiation | emission immunity test apparatus shown in FIG. The figure explaining the moving speed of the antenna which concerns on embodiment. The figure which shows the applied electric field strength distribution which concerns on embodiment. The figure which illustrates the movement range of the antenna which concerns on embodiment. The figure explaining the radiation immunity test method concerning a comparative example. The figure explaining a uniform electric field side. The figure which shows the applied electric field strength distribution which concerns on a comparative example. The figure explaining the excess and deficiency of the electric wave application by the position control deviation based on a comparative example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, a radiation immunity test method according to a comparative example of the present invention will be described with reference to FIGS.
FIG. 6 shows an outline of the radiation immunity test method according to the comparative example. In the radiated immunity test method according to the comparative example, as shown in FIG. 6, radio waves are radiated to the device under test 69 from the antenna 61 located in the vicinity thereof. The electric field intensity of the radio wave radiated from the antenna 61 is inversely proportional to the distance, and attenuates rapidly as the distance increases. Therefore, the area where the electric field strength of the radio wave is within the specified range at the surface position of the device under test 69 is smaller than the surface of the device under test 69 (corresponding to the test range). A region where the electric field strength is within a specified range within a certain plane is called a uniform electric field plane. FIG. 7 shows the uniform electric field surface. In FIG. 7, an area written as -1 [dB] indicates an area in which the deviation from the maximum value of the electric field intensity is within -1 [dB] in this plane. The uniform electric field surface is defined as a region where the deviation from the maximum value of the electric field strength is within −4 [dB], for example.

  In the radiation immunity test method according to the comparative example, the surface of the device under test 69 is divided into a plurality of partial areas so that each partial area has a uniform electric field surface, and the test of applying an electric field to each partial area is repeated. In the example shown in FIG. 6, the surface of the device under test 69 is divided into 64 partial areas of 8 rows and 8 columns indicated as partial areas A1, A2, and so on. For example, the test is performed in the order of partial area A1, partial area A2, ..., partial area A8, partial area A9, .... Specifically, first, the antenna 61 is moved and stopped at a position facing the partial area A1, radiation of the radio wave from the antenna 61 is started, and radiation of the radio wave is stopped after a predetermined time has elapsed. Next, the antenna 61 is moved to stop at a position facing the partial area A2, radiation of radio waves from the antenna 61 is started, and radiation of radio waves is stopped after a predetermined time has elapsed. This operation is repeated for all partial regions. In this case, the distribution of the electric field intensity applied to the test range is as shown in FIG. In FIG. 8, square squares indicate partial areas.

  However, in the radiation immunity test method according to the comparative example, it is necessary to arrange the antenna 61 and perform many tests for applying an electric field for a specified time, which requires a great deal of effort and time for the test. In addition, it is conceivable that the position of the antenna 61 is shifted with respect to the partial region, and a range in which an electric field is not applied appears. As shown in FIG. 9, when the accuracy of the position control is insufficient and the antenna 61 passes from a predetermined application position, a range in which the application of the electric field is not performed and a range in which the application of the electric field is overlapped occur. . In order to prevent this, highly accurate position control is required for movement and stop of the antenna. Furthermore, there is a maximum of 4 [dB] in the uniform electric field plane, and there is a possibility that the immunity may be over-estimated in the place where the electric field strength is low.

  Next, a radiation immunity test method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5.

  FIG. 1 schematically shows a radiation immunity test apparatus 10 according to the present embodiment. As shown in FIG. 1, the radiation immunity test apparatus 10 includes an antenna 11 as a radiating element that radiates radio waves into the air, a moving device 12 for moving the antenna 11, and a control device 13 for controlling the moving device 12. A region 15 indicates an application range of radio waves from the antenna 11.

  The mobile device 12 includes, for example, a mobile platform that supports the antenna 11 so as to be movable along two mutually orthogonal axes. In the example of FIG. 1, the moving device 12 includes a member 122 fixed to a base (not shown) and extending in the lateral direction, a member 121 attached to the member 122 so as to be movable along the member 122, and a member The antenna 11 is fixed to the member 123. The member 124 is fixed to the member 121 and extends in the vertical direction. The member 123 is attached to the member 124 so as to be movable along the member 124. The antenna 11 can be moved in the horizontal direction by moving the member 121, and the antenna 11 can be moved in the vertical direction by moving the member 123. The moving device 12 is installed so that the antenna 11 can be moved away from the surface of the device under test 29 (corresponding to the test range) by a predetermined distance as shown in FIG. The antenna 11 is disposed in the vicinity of the device under test 29. For example, the moving device 12 is installed such that the device under test 29 is located in the near field, that is, the distance between the antenna 11 and the surface of the device under test 29 is smaller than λ / 2π. Here, λ represents the wavelength of the radio wave.

  The radiation immunity test apparatus 10 further includes a signal generator 22 and an amplifier 21. The signal generator 22 is controlled by the control device 13. The signal generator 22 generates a signal necessary for the immunity test. As a signal, for example, a signal subjected to AM (Amplitude Modulation) modulation or pulse modulation is used. The generated signal is amplified by the amplifier 21 to a level at which the electric field strength defined by the test method can be applied. The amplified signal is fed to the antenna 11 and radiated from the antenna 11 into the air. Radio waves radiated from the antenna 11 propagate in space and are applied to the device under test 29. At this time, a region in which the electric field strength is within the specified range at the surface position of the device under test 29 is called a uniform electric field surface, which is defined as an application range. The size of the application range depends on the distance between the antenna 11 and the surface of the device under test 29 or the like. Typically, the application range is square and the longitudinal dimension and the lateral dimension are the same.

Next, the operation of the radiation immunity test apparatus 10 will be described.
In the present embodiment, the antenna 11 is moved by the moving device 12 while radiating radio waves from the antenna 11. For example, the antenna 11 facing the upper left portion of the surface of the device under test 29 is moved to the right, and when it reaches the right end portion of the surface of the device under test 29, it moves down and further moves to the left. When it reaches the left edge of the surface, move it down. Here, the distance by which the antenna 11 is moved down coincides with the vertical dimension of the application range. In this way, the surface of the device under test 29 is scanned comprehensively.

  When the antenna 11 moves in the horizontal direction while radiating radio waves, the application range 15 also moves. At this time, by adjusting the moving speed of the antenna 11 by the control device 13, it becomes possible to apply an electric field of specified strength to the device under test 29 for specified time. The velocity is l / t [cm / sec], where l [cm] is the lateral dimension of the application range and t [sec] is the prescribed time, as shown in FIG. In this case, it takes t [sec] until the right end of the application range reaches an arbitrary linear area 33 and the left end leaves the linear area 33, that is, the electric field is applied to the linear area 33 for t [sec]. Is applied. In this case, since the distribution of the electric field strength also moves, the distribution of the applied electric field strength is as shown in FIG. 4, and the lateral strength of the electric field depending on the place is offset. For this reason, only the moving speed and the up and down movement are required for the high precision control, and the high precision device is not required for the lateral position control.

  FIG. 5 illustrates the moving range of the antenna 11 according to this embodiment. As shown in FIG. 5, in order to apply an electric field also to the end of the device under test 29 for a prescribed time, the antenna 11 has the antenna position (specifically, the central position of the radiation surface) at the device under test. It is controlled to move from a position P1 that is 1/2 [cm] outside the end of 29 to a position P2 that is 1/2 [cm] outside the other end of the device under test 29. In this way, an electric field can be applied for a prescribed time over the entire partial region. Also, when moving the antenna 11 in the vertical direction, for example, when the antenna 11 moves downward from the position P2 to the position P3, it is not necessary to stop radio wave radiation from the antenna 11.

  In the present embodiment, the movement of the antenna 11 is laterally directed in order to offset the lateral strength of the applied electric field, but the present invention is not limited to this. In another embodiment, it is also possible to make the movement of the antenna 11 longitudinal, in order to offset the longitudinal strength of the applied field.

  As described above, according to the present embodiment, the antenna is controlled to move in the lateral direction at a constant speed in the state of radiating radio waves. This makes it possible to apply a defined electric field strength for a defined time over the entire test range, and enables a radiated immunity test method that assumes that the radiation source is used in the vicinity of the electronic device. Further, since it is not necessary to repeat the test of stopping the antenna and radiating the radio wave for a specified time for each partial region where the test range is divided as in the comparative example, the test time can be shortened. Furthermore, since highly accurate position control is not required, it is possible to use an inexpensive control device, and there is no region where application of an electric field is excessive or insufficient within the test range. Furthermore, since the deviation of the electric field intensity in the uniform electric field plane is offset, the overestimation of the immunity is reduced.

  The present invention is not limited to the above embodiments as it is, and at the implementation stage, the constituent elements can be modified and embodied without departing from the scope of the invention. In addition, various inventions can be formed by appropriate combinations of a plurality of components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in each embodiment. Furthermore, you may combine suitably the component covering different embodiment.

DESCRIPTION OF SYMBOLS 10 ... Radiation immunity test apparatus, 11 ... Antenna, 12 ... Mobile device, 13 ... Control apparatus, 15 ... Application range, 21 ... Amplifier, 22 ... Signal generator, 29 ... Device under test, 3 ... Linear area | region, 61 ... Antenna, 69: Device under test.

Claims (6)

A radiating element that radiates radio waves;
Moving means for moving the radiating element in a first direction and a second direction intersecting each other;
Control means for controlling the moving means such that the radiation element moves at a constant speed in the first direction in a state where the radio wave is emitted;
Radiation immunity test device comprising:   The control means moves the radiation element in the first direction from one end of the test range from the outside by half of the dimension of the application range to the outside by the half of the dimension of the application range from the outside by half the dimension of the application range. Moving the radiating element in the second direction by a dimension of the application range, the application range being set based on a distance between the radiating element and the test range. Item 2. The radiation immunity test apparatus according to item 1.   The radiation immunity test apparatus according to claim 1, wherein the moving means is installed such that a distance between the radiation element and a test range is smaller than λ / 2π, where λ is a wavelength of the radio wave. A radiation immunity test method executed by a radiation immunity test apparatus comprising: a radiation element that radiates radio waves; and a moving unit that moves the radiation element in a first direction and a second direction that intersect with each other.
The radiation immunity test method which controls the said transfer means so that the said radiation | emission element moves at a fixed speed in the said 1st direction in the state which radiates | emitted the said electromagnetic wave.   The controlling of the moving means may include moving the radiating element in the first direction from one end of the test range by half of the dimension of the application range to the outside of the other end of the test range by half of the dimension of the application range. Moving the radiating element in the second direction by a dimension of the application range, the application range being set based on a distance between the radiating element and the test range. The radiated immunity test method according to claim 4.   The radiation immunity test method according to claim 4, further comprising installing the moving means such that the distance between the radiation element and the test range is smaller than λ / 2π, wherein λ is a wavelength of the radio wave.